LAUSR

BACKGROUND Ornithine transcarbamylase deficiency (OTCD) is a common ornithine cycle disorder, and OTC gene variation is the main pathogenic factor of this disease. This study explored and validated a variant in the OTC gene. CASE SUMMARY The neonate exhibited high blood ammonia, lactic acid, and homocysteine levels on the fifth day after birth. A novel deletion variant in the OTC gene [NM_000531.5, c.970_979delTTCCCAGAGG, p.Phe324GlnfsTer16] was uncovered by exome sequencing. The variant caused a protein-coding frameshift and resulted in early translation termination at the 16th amino acid after the variant site. CONCLUSION Our results provide a novel pathogenic variant in OTC and related clinical features for further OTCD screening and clinical consultation.